Should I be okay with his close female friend moving in with him?

My boyfriend of a year and a half is renting out a house to two males and currently looking for a third roomate to help cover money woes and live in the third bedroom. He has rented to females before and I was fine with this. This situation is a little different to me because the woman in question is one of his best friends (a plus) but I feel uncomfortable because I know that they have had a romantic encounter in the past (about a year before he was with me). He says it was a one time thing.
When we first started dating she was overly protective of him, and he told me she had disliked all of his former girlfriends. She made a point of letting me know she was important to him, and i was fine with that. We get along fine and hang out in groups, and they hang out one on one sometimes. He admitted that she used to cuddle up to him while watching movies alone but says it was justified because she "needed her friend" after going through a tough breakup. I accepted this with gritted teeth. I can't stand the idea of my boyfriend cuddling with another woman when I am not there, but want to trust him and have a healthy relationship. We discussed my feelings about it and he has agreed to respect my ideas of boundaries on the issue.
But now they are talking about her moving into his house, where I do not live. He had asked me to move in first but i felt it was too early in our relationship ( I am 22 and in school, he is 27).
My question is this: Are my feelings of jealously unwarranted? Would it be unreasonable for me to object to this? Does being in a trusting, open relationship mean I should trust him beyond all doubt and dismiss my feelings of discomfort on the issue?
Help!

By 1xoxfireflyxox 8 years ago :: Dating
  • Robert Betancourt
    MA, Professional Counseling,Therapist
    Emotional Healing-25+ years experience in helping people find solutions that work. "one of the best therapists here" $2.49/minute
       4.93/5
  • Milton Mankoff
    Ph.D.; LMSW
    Misunderstandings can create or escalate conflicts, but genuine incompatibility can also exist within relationships. Non-judgmental. LGHBTQIA-supportive. $2.75/minute
       4.92/5
  • View More Experts
    5